DNA methylation is a ubiquitous biological process that occurs in diverse organisms ranging from bacteria to humans. During this process, DNA methyltransferases catalyze the post-replicative addition of a methyl group to the N6 position of adenine or the C5 or N4 position of cytosine, for which S-adenosylmethionine is the universal donor of the methyl group. In higher eukaryotes, DNA methylation plays a role in genomic imprinting and embryonic development. In addition, aberrations in DNA methylation have been implicated in aging and various diseases including cancer.
Therefore, there is a need for methods of determining the methylation profile of an individual cell or organism. The present invention addresses this and other problems.